1. Field of the Invention
The present invention relates generally to a foldable frame, and more particularly to an innovative design of a pitman-style foldable frame.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
Foldable frames are widely used in products like chairs, tables, sleds, etc, so that the products can be folded to a smaller overall size to save storage space when they are not used.
In the structural design of prior-art foldable frames, it is common to use cross connecting rods for folding and moving. However, in actual applications, it is found that such a structural design has the disadvantage of high material cost because the length of each cross connecting rod has to be considerably longer than half of the length of the foldable frame area. Moreover, the longer the cross connecting rods are, there will be more deformation and less support in the middle section of the rods, causing problems and disadvantages of insufficient support strength and lower rigidity.
Thus, to overcome the aforementioned problems of the prior art, it would be an advancement if the art to provide an improved structure that can significantly improve the efficacy.
Therefore, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products.